英语必修三第四单元句型与难句分析导学案.doc

Book 3 Unit 4 Astronomy: the Science of the Stars句型与难句分析导学案（教师版）1 学习目标：通过练习，掌握文章重点句型与难句并学会分析句子结构。2 学习过程I. 难句分析1. What it was to become was uncertain until between 4.5 and 3.8 billion years ago when the dust settled into a solid globe. 它会变成什么还没有人知道，直到38-45亿年前，这团尘埃才慢慢地形成一个固体的球状物。句式分析What it was to become是由what引导的主语从句，what在从句中作become的表语。What引导主语从句时，可在从句中作主语、宾语或表语。例句What puzzles him is that no one knows that famous actor in the town.使他疑惑的是这个镇上没人认识那个知名演员。运用 他想要成为的是一名英语老师。What he wants to become is an English teacher. 不清楚他想要跟我们说什么。What he wants to tell us is not clear.2. This produced a chain reaction, which made it possible for life to develop. 这就产生了一系列的反应，使得生命就有可能开始发展了。句式分析make it possible for sb. to do sth. 意为“使某人做某事成为可能”，该结构中make作使役动词。其中it作形式宾语，真正的宾语是后面的不定式复合结构。与make有相似用法的动词还有think, find, consider, feel等；可用于该结构的形容词还有likely, impossible等。如：例句I think it necessary to make a full plan before we start.我认为在我们开始之前制定一个计划是有必要的。运用网络使我们有可能用更少的时间从其他国家获得更多的信息。The Internet has made it possible for us to get more information from others in much less time.这本书使我用一种简单的方式学习英语。The book makes it possible for me to learn English in a easy way.我们认为他可能会在表演开始之前离开。We think it possible for him to leave before the show starts.3. But when I tried to step forward, I found I was carried twice as far as on the earth and fell over. 而当我试着向前迈步时，我发觉我被送出很远，步子的跨度竟是在地球上的两倍，因而我摔倒了。句式分析twice as far as 意为“是.的两倍”，其结构为：A+be/ do+倍数+as+形容词/ 副词原级+as+B，表示“A是B的多少倍”。拓展 1）A+be/do+倍数+形容词/副词的比较级+than+B； 2）A+be+倍数+the size/height/length/width+of+B； 3）A+be+倍数+what从句例句Asia is four times as large as Europe. =Asia is four times the size of Europe. =Asia is three times larger than Europe. 亚洲面积是欧洲的四倍（比欧洲大三倍）。运用这辆小汽车的速度比那辆大卡车快两倍。The car runs twice faster than that truck.这条街道是那条的四倍长。This street is four times the length of that street. 这棵树是那棵的三倍高。This tree is three times the height of that tree.4. It was not immediately obvious that water was to be fundametal to the development of life. 水对于生命的发展会起关键作用，这一点在当时并不明显。句式分析It is obvious that.（=Obviously./ It is quite clear that）显然.运用很显然他感冒了。It is obvious that he is suffering from a bad cold.显然他昨天没有说实话。Obviously he did not tell the truth yesterday.5. We watched, amazed as fire broke out on the outside of the spaceship as the earths gravity increased. 我们惊奇地看着，随着地球引力的增加，宇宙飞船的外层燃烧起火。句式分析在本句中，amazed是过去分词作伴随状语。与现在分词作伴随状语不同 ，过去分词作状语表示分词动作与逻辑主语构成动宾关系或动作已完成，而现在分词作状语表示分词动作与逻辑主语是主动关系或动作正在进行。例句Aunt Wu came in, followed by her daughter. 吴阿姨走进来，（她）后面跟着他的女儿。He sat by the roadside, begging.他坐在路边乞讨。运用“We cant go out in this weather,” Ben said, looking out （向外看）of the window.He stared at the accident scene, shocked at (被震惊）the tragedy.佳句仿写What many scientists believe is that the continued presence of water allowed the earth to dissolve harmful gases and acids into the oceans and seas. 很多科学家相信，由于地球上长期有水存在，使地球得以把有害气体和酸性物质溶解在海洋里。句式主语从句+is+that引导的表语